From ae1be05dde0d3c00a809018efd79500fc208e038 Mon Sep 17 00:00:00 2001
From: James Couball <jcouball@yahoo.com>
Date: Tue, 29 Jan 2019 17:31:49 -0800
Subject: [PATCH] Do not allow changes to ENV to leak from test to test

Signed-off-by: James Couball <jcouball@yahoo.com>
---
 tests/test_helper.rb                          | 16 ++++-
 tests/units/test_config.rb                    | 36 ++++++------
 tests/units/test_lib.rb                       | 58 ++++++++++---------
 ..._thread_safty.rb => test_thread_safety.rb} |  0
 4 files changed, 65 insertions(+), 45 deletions(-)
 rename tests/units/{test_thread_safty.rb => test_thread_safety.rb} (100%)

diff --git a/tests/test_helper.rb b/tests/test_helper.rb
index ef739d32..3f5a4665 100644
--- a/tests/test_helper.rb
+++ b/tests/test_helper.rb
@@ -79,5 +79,19 @@ def append_file(name, contents)
       f.puts contents
     end
   end
-  
+
+  # Runs a block inside an environment with customized ENV variables.
+  # It restores the ENV after execution.
+  #
+  # @param [Proc] block block to be executed within the customized environment
+  #
+  def with_custom_env_variables(&block)
+    saved_env = {}
+    begin
+      Git::Lib::ENV_VARIABLE_NAMES.each { |k| saved_env[k] = ENV[k] }
+      return block.call
+    ensure
+      Git::Lib::ENV_VARIABLE_NAMES.each { |k| ENV[k] = saved_env[k] }
+    end
+  end
 end
diff --git a/tests/units/test_config.rb b/tests/units/test_config.rb
index f30278df..7721ba24 100644
--- a/tests/units/test_config.rb
+++ b/tests/units/test_config.rb
@@ -29,27 +29,29 @@ def test_set_config
   end  
 
   def test_env_config
-    assert_equal(Git::Base.config.git_ssh, nil)
-    
-    ENV['GIT_SSH'] = '/env/git/ssh'
+    with_custom_env_variables do
+      begin
+        assert_equal(Git::Base.config.git_ssh, nil)
+        ENV['GIT_SSH'] = '/env/git/ssh'
 
-    assert_equal(Git::Base.config.git_ssh, '/env/git/ssh')
+        assert_equal(Git::Base.config.git_ssh, '/env/git/ssh')
 
-    Git.configure do |config|
-      config.binary_path = '/usr/bin/git'
-      config.git_ssh = '/path/to/ssh/script'
-    end
-    
-    assert_equal(Git::Base.config.git_ssh, '/path/to/ssh/script')
+        Git.configure do |config|
+          config.binary_path = '/usr/bin/git'
+          config.git_ssh = '/path/to/ssh/script'
+        end
+
+        assert_equal(Git::Base.config.git_ssh, '/path/to/ssh/script')
 
-    @git.log
-  ensure
-    ENV['GIT_SSH'] = nil
+        @git.log
+      ensure
+        ENV['GIT_SSH'] = nil
 
-    Git.configure do |config|
-      config.binary_path = nil
-      config.git_ssh = nil
+        Git.configure do |config|
+          config.binary_path = nil
+          config.git_ssh = nil
+        end
+      end
     end
   end
-  
 end
diff --git a/tests/units/test_lib.rb b/tests/units/test_lib.rb
index 25e42022..8796dc88 100644
--- a/tests/units/test_lib.rb
+++ b/tests/units/test_lib.rb
@@ -75,40 +75,44 @@ def test_log_commits
     a = @lib.full_log_commits :count => 20
     assert_equal(20, a.size)
   end
-  
+
   def test_environment_reset
-    ENV['GIT_DIR'] = '/my/git/dir'
-    ENV['GIT_WORK_TREE'] = '/my/work/tree'
-    ENV['GIT_INDEX_FILE'] = 'my_index'
+    with_custom_env_variables do
+      ENV['GIT_DIR'] = '/my/git/dir'
+      ENV['GIT_WORK_TREE'] = '/my/work/tree'
+      ENV['GIT_INDEX_FILE'] = 'my_index'
 
-    @lib.log_commits :count => 10
+      @lib.log_commits :count => 10
 
-    assert_equal(ENV['GIT_DIR'], '/my/git/dir')
-    assert_equal(ENV['GIT_WORK_TREE'], '/my/work/tree')
-    assert_equal(ENV['GIT_INDEX_FILE'],'my_index')
+      assert_equal(ENV['GIT_DIR'], '/my/git/dir')
+      assert_equal(ENV['GIT_WORK_TREE'], '/my/work/tree')
+      assert_equal(ENV['GIT_INDEX_FILE'],'my_index')
+    end
   end
 
   def test_git_ssh_from_environment_is_passed_to_binary
-    ENV['GIT_SSH'] = 'my/git-ssh-wrapper'
-
-    Dir.mktmpdir do |dir|
-      output_path = File.join(dir, 'git_ssh_value')
-      binary_path = File.join(dir, 'git')
-      Git::Base.config.binary_path = binary_path
-      File.open(binary_path, 'w') { |f|
-        f << "echo $GIT_SSH > #{output_path}"
-      }
-      FileUtils.chmod(0700, binary_path)
-      @lib.checkout('something')
-      assert_equal("my/git-ssh-wrapper\n", File.read(output_path))
-    end
-  ensure
-    Git.configure do |config|
-      config.binary_path = nil
-      config.git_ssh = nil
-    end
+    with_custom_env_variables do
+      begin
+        ENV['GIT_SSH'] = 'my/git-ssh-wrapper'
 
-    ENV['GIT_SSH'] = nil
+        Dir.mktmpdir do |dir|
+          output_path = File.join(dir, 'git_ssh_value')
+          binary_path = File.join(dir, 'git')
+          Git::Base.config.binary_path = binary_path
+          File.open(binary_path, 'w') { |f|
+            f << "echo $GIT_SSH > #{output_path}"
+          }
+          FileUtils.chmod(0700, binary_path)
+          @lib.checkout('something')
+          assert_equal("my/git-ssh-wrapper\n", File.read(output_path))
+        end
+      ensure
+        Git.configure do |config|
+          config.binary_path = nil
+          config.git_ssh = nil
+        end
+      end
+    end
   end
 
   def test_revparse
diff --git a/tests/units/test_thread_safty.rb b/tests/units/test_thread_safety.rb
similarity index 100%
rename from tests/units/test_thread_safty.rb
rename to tests/units/test_thread_safety.rb